Perform the following supportive services: (1) Immuno-Biochemical diagnostic development for cunial application (2) Testing compounds selected by LTCB Staff for quantitative inhibition of transforming activity of sarcoma viruses (3) Provide tissue culture support to NCI Staff for cloning human leukemia and other cancer cells, for establishing skin fibroblasts in culture from selected leukemia patients, and for labeling mammalian cells with radioactive isotopes.